I short circuited the 3V3, 5V0, and the 12V rail in turn. The power supply did shut down, and once the short was removed and the unit switched off for at least one second, resumed normal operation. Although listed here at the beginning of the testing section, I tend to leave this test until the very end, in case it doesn't quite go to plan.

DC Output Voltage Load Regulation:

Mains Input Voltage 110VAC

Ultra X4 600W Power Supply DC Output Voltage Load Regulation

Supply = 110VAC/50Hz

PSU DC Rail

Measured Voltage(V)

3V3

3.30

5V0

5.12

+12V

12.30

-12V

9.84

5VSB

4.95

Total PSU Loading = Approx. 25W (1 x WD800 IDE HDD)

Ultra X4 600W Power Supply DC Output Voltage Load Regulation

Supply = 110VAC/50Hz

PSU

DC Rail

Rail Loading Amps (A)

Rail Loading Watts (W)

Measured Voltage (V)

ATX12V V2.2 Limits (V)

Pass/Fail

+3V3

3.13

10.27

3.28

3.135 – 3.465

Pass

+5V

4.83

24.58

5.09

4.75 – 5.25

Pass

+12V

5.16

63.26

12.26

11.4 – 12.6

Pass

-12V

0.34

3.97

11.68

10.8 – 13.2

Pass

+5VSB

2.04

10.04

4.92

4.75 – 5.25

Pass

Total PSU Loading = 112W (19% of Rated Maximum Output Power)

Ultra X4 600W Power Supply DC Output Voltage Load Regulation

Supply = 110VAC/50Hz

PSU

DC Rail

Rail Loading Amps (A)

Rail Loading Watts (W)

Measured Voltage (V)

ATX12V V2.2 Limits (V)

Pass/Fail

+3V3

8.41

27.50

3.27

3.135 – 3.465

Pass

+5V

9.78

49.19

5.03

4.75 – 5.25

Pass

+12V

18.66

227.82

12.21

11.4 – 12.6

Pass

-12V

0.36

4.29

11.93

10.8 – 13.2

Pass

+5VSB

2.08

10.15

4.88

4.75 – 5.25

Pass

Total PSU Loading = 319W (53% of Rated Maximum Output Power)

Ultra X4 600W Power Supply DC Output Voltage Load Regulation

Supply = 110VAC/50Hz

PSU

DC Rail

Rail Loading Amps (A)

Rail Loading Watts (W)

Measured Voltage (V)

ATX12V V2.2 Limits (V)

Pass/Fail

+3V3

13.56

43.93

3.24

3.135 – 3.465

Pass

+5V

15.25

75.64

4.96

4.75 – 5.25

Pass

+12V

36.51

444.33

12.17

11.4 – 12.6

Pass

-12V

0.36

4.41

12.26

10.8 – 13.2

Pass

+5VSB

2.05

9.92

4.84

4.75 – 5.25

Pass

Total PSU Loading = 578W (96% of Rated Maximum Output Power)

Mains Input Voltage 230VAC

Ultra X4 600W Power Supply DC Output Voltage Load Regulation

Supply = 230VAC/50Hz

PSU DC Rail

Measured Voltage(V)

3V3

3.30

5V0

5.12

+12V

12.30

-12V

9.83

5VSB

4.92

Total PSU Loading = Approx. 25W (1 x WD800 IDE HDD)

Ultra X4 600W Power Supply DC Output Voltage Load Regulation

Supply = 230VAC/50Hz

PSU

DC Rail

Rail Loading Amps (A)

Rail Loading Watts (W)

Measured Voltage (V)

ATX12V V2.2 Limits (V)

Pass/Fail

+3V3

3.15

10.33

3.28

3.135 – 3.465

Pass

+5V

4.83

24.58

5.09

4.75 – 5.25

Pass

+12V

5.16

63.26

12.26

11.4 – 12.6

Pass

-12V

0.34

3.97

11.68

10.8 – 13.2

Pass

+5VSB

2.04

10.06

4.93

4.75 – 5.25

Pass

Total PSU Loading = 112W (19% of Rated Maximum Output Power)

Ultra X4 600W Power Supply DC Output Voltage Load Regulation

Supply = 230VAC/50Hz

PSU

DC Rail

Rail Loading Amps (A)

Rail Loading Watts (W)

Measured Voltage (V)

ATX12V V2.2 Limits (V)

Pass/Fail

+3V3

8.27

27.04

3.27

3.135 – 3.465

Pass

+5V

9.76

49.09

5.03

4.75 – 5.25

Pass

+12V

18.69

228.39

12.22

11.4 – 12.6

Pass

-12V

0.36

4.29

11.92

10.8 – 13.2

Pass

+5VSB

2.08

10.15

4.88

4.75 – 5.25

Pass

Total PSU Loading = 319W (53% of Rated Maximum Output Power)

Ultra X4 600W Power Supply DC Output Voltage Load Regulation

Supply = 230VAC/50Hz

PSU

DC Rail

Rail Loading Amps (A)

Rail Loading Watts (W)

Measured Voltage (V)

ATX12V V2.2 Limits (V)

Pass/Fail

+3V3

13.50

43.74

3.24

3.135 – 3.465

Pass

+5V

14.88

73.80

4.96

4.75 – 5.25

Pass

+12V

36.66

446.15

12.17

11.4 – 12.6

Pass

-12V

0.36

4.41

12.26

10.8 – 13.2

Pass

+5VSB

2.05

9.92

4.84

4.75 – 5.25

Pass

Total PSU Loading = 578W (96% of Rated Maximum Output Power)

The Ultra X4 600W power supply refused to fire up with no load present, rare but not abnormal power supply behavior, and rather than skip, the no load test it was loaded to a low level with a single Western Digital IDE HDD pulling approximately 25W. This load was obviously not quite enough to wake the power supply up with a -12V rail voltage of only 9.84V.

The DC output voltage load regulation of the Ultra X4 600W power supply is very good and all readings fall well within the limits set down by the ATX12V V2.2 specification but it is however the first power supply I have tested that failed to reach 5.0V on the +5VSB rail.